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AH540; AH541

Secondary Control Units
Air Handler Controllers
Date Last Saved: 1/24/2006 9:07:53 AM

Product Name(s): AH540; AH541
Product Description: The AH controller is a stand alone or door mounted controller specifically designed for air handling units. • AH540: factory installed • AH541: field installed
Product Application(s): The AH540/541 controller conforms to the LonMark Space Comfort Controller profile or the Discharge Air Controller profile. Possible air-handler configurations for both controllers include: - cooling only unit - heating only unit* - heating and cooling unit* * all with or without bypass for each coil
Point Quantity Characteristics
Analog Input (AI): See Below • Thermistor
• RTD (mixed air only)
Digital Input (DI): See Other
Universal Input (AI or DI): N.A.
Analog Output (AO): See Below 0 to 10 VDC
Predefined outputs:
- Supply Fan Speed
- Heat Output
- Fan and Bypass Damper
- Outdoor Air Damper
- Cool Valve output
- 2-pipe change over
Digital Output (DO): See Other
Universal Output (UO):
Control Unit Model #:AIDIUIDOAOUOOther
AH 540 8 6 9
AH 541 8 6 9
A/D Converter Resolution
8 bit
10 bit
12 bit
16 bit
D/A Converter Resolution
6 bit
8 bit
10 bit
No Analog Output
Other information not provided
HOA switches provided on each output?
Note: These are also available as an add-on from 3rd party vendors.
Both AO and DO
DO Only
Indicating status LED on each output?
AO and DO
AO Only
DO Only
Integral Flow Sensor? N.A.
Integral Damper Actuator? N.A.
Can controller accept occupant override from thermostat? N.A.
Can controller accept occupancy sensor input? N.A.
Expander Boards N.A.
Network Ports, Protocol(s), and Speed(s) Supported
(Note: See 'Architecture' for network details)
(1) - LonTalk TP/FT -10 @ 78.6 Kbps
External Communication Ports, Speeds and Access Devices (1) - Optional operator display
(1) - Rover Service tool
Additional Information (Optional)
Network Accessing Capabilities via Controller
Access controller only
Access controller plus additional controllers on network segment / LAN
Access all controllers on system
No access available on this controller
Controller Access Devices
Local Display Panel (controller-mounted)
Local Display Panel (zone-mounted)
Handheld Interface Device (proprietary device)
PDA (3rd-Party HID)
Zone-Based port (details below)
Zone-Based Interface Access N.A.
Zone Interface Hardware
Zone-Mounted touchpad (thermostat or stand-alone display)
HID (proprietary device)
PDA (3rd party HID, with software)
*Note: This section covers the capabilities for accessing the controller or other parts of the network from the controller (i.e. 'bottom-up').
Standard access functionality is covered in the Architecture and Software sections.
**Does NOT include front-end OI functions. See vendor for specific functions available.
Functions Available Through Field Interface**:View ParamsChange ParamsChange
O&M SupportTAB/Cx Support
Local Display Panel (controller-mounted)
Local Display Panel (zone-mounted)
Handheld Interface Device (proprietary device)
PDA (3rd-Party HID)
Zone-Based port (details below)
Microprocessor(s) Motorola 68332 QFP
Clock Type
Powered, battery-backed
Battery powered
Powered, no battery backing
Other Super-capacitor backed
Clock Synchronization Crystal controlled
Volatile Memory (RAM) Capacity 512K
Volatile Memory (RAM) Uses
RAM use unrestricted
RAM use restricted as shown below
Information Not Provided
Program Execution / Calculation storage
Data / Trends / Alarms storage
Configuration / Parameter storage
Control Programming storage
Is Volatile Memory Supported By Battery? No
Battery Type(s) Not required - clock backed by super-capacitor all other programs backed by non-volative memory.
Battery Life N.A.
Backup Battery Operating Time Clock can operate for three days under normal operating conditions.
Non-Volatile Memory Capacity (EEPROM/Flash)* FLASH - 2 MB
Non-Volatile Memory Uses
Data / Trends / Alarms / Calculation Storage
Configuration / Parameter Storage
Control Programming Storage
Controller Operating System
Additional Information
* Items in NV memory are not lost upon power or battery failure. Other types of NV memory such as EPROM, NOVROM, etc. do not directly impact system performance.
Can trend data be stored in this controller? No
How many total trend values can be stored? N.A.
What is the controllers role in trending? Provide data to SI unit for trending
Can controller be programmed to 'push' data to archive or are trends 'pulled' from controller?
When full, does controller automatically send up trend data, overwrite data, or stop logging data? N.A.
Programming Method(s) The AH540/541 controller is an Application Specific Controller and is not programmable. Trane's Rover service tool is used to configure the AH540/541 controller.
Resident vs Non-Resident Program Execution Resident program execution
Resident/Supervisory. This controller supervises the scheduling of other controllers.
Resident/Stand Alone. This controller contains its own schedule.
Non-Resident. This controller is dependent upon another controller for its schedule.
None. This controller has no scheduling features.
Resident Energy Management
Energy management algorithms for this controller can be custom programmed
Pre-programmed/built-in algorithms available, and are fully editable using custom programming
Pre-Programmed/built-in with limited editing via template-based programming
Controller is not typically used for energy management functions
Specific Pre-Programmed Algorithms Available
None (custom programming only)
None (not applicable)
Optimal Start/Optimal Stop
Peak Demand Limiting/Load Shedding
Economizer (enthalpy, dry-bulb, CO2, modulating/2-position, etc.)
Additional Energy Management functions are resident at SI
Additional Programming Functions
DDC Loops (P, PI, PID) PID
Automatic PID Tuning Feature No
Automatical-Dial Alarm Support This function is performed by the SI unit.
Does controller perform multiple retries and buffer/store alarm until connection is made? Yes
Are multiple destinations possible? Yes
Upon controller power loss or hardware failure:
Are network communications affected? No
Is loss recognized on/by the network and alarm reported? Yes
DO and AO response?
Outputs fail to a user pre-specified position
Outputs fail to a normal (unpowered) position
Outputs fail to last position
Volatile memory functions?
Retained for life of backup battery
Upon restoration of power does the controller:
Auto-reboot without operator intervention? Yes
Automatically reset/synchronize the clock? Yes when the controller has the optional operator display.
Update all monitored functions? Yes
Generate an alarm if backup battery is dead? N.A.
Upon network or communications failure does controller:
Continue to operate standalone? Yes
Operate with last global settings or user-specified value? N.A.
Do broken network segments continue to communicate within the remaining segment?
(Note: May depend on proper termination of segments for higher speed networks.)
Does network automatically reconfigure upon restoration? The LON bindings are not lost during network failure. No reconfiguration is needed.
Does network store 'loss of communications' alarm with time of event? Yes, this is performed by the SI unit.
Additional Information (optional)
Self Test Diagnostics
Does controller have internal self-test diagnostics to check:
Processor failure? Yes
Internal hardware failure? Yes
Open/shortened sensor? Yes
Control Enclosure NEMA-1
Power Supply Required
Voltage 24/120/230 VAC
18-32 VAC
98-132 VAC
196-264 VAC
VA Control board 13 VA
Operator display 7 VA
Surge Protection Meets CE surge requirements for industrial environments
Underwriters Laboratories AH540:
- UL 873 temperature indicating and regulating equipment
- CUL C22.2 No. 24-93 temperature indicating and regulating equipment

- UL 916 Energy Management
- CUL C22.2 No. 205-M1985 Signal Devices
FCC AH540: CRF 47, Part 15, Subpart A, Class A & B

AH541: CFR 47, Part 15, Subpart A, Class A
CE AH540:
- Conducted emissions; EN55022 Class A & Class B, EN61000-3-2, EN61000-3-3
- Radiation emissions; EN55022 Class A, Immunity; EN50082-2 industrial
LonMark Certified
Yes LonMark Version 3.3
No - but LonWorks compatible
Information not provided
BACnet (BTL) Certified
Not submitted for testing
Information not provided